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0 pointsars5y ago0 comments

Gravitational attraction is a function of both objects, so the force between them is not a constant, same as for the electron.

Also, what if you have a charge so high that the electrical-escape velocity exceeds the speed of light? A strange kind of black hole?

I ask these things because I do not understand why gravity is called "not a force", while electromagnetism is, when I see no real difference between how particles act.

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caf5y ago

Gravitational attraction is a function of both objects, so the force between them is not a constant, same as for the electron.

The way that varies is always in proportion to the object's inertial mass though, which has the result that the path traced by an any object with the same starting position and velocity in a given gravitational field is going to be the same.

Contrast this with charge, which can vary independently of inertial mass. This has the result that the paths traced by objects with the same starting position and velocity in a given electrical field will vary.

This also means there is no fixed "electrical escape velocity". More massive objects with the same charge can escape with a lower velocity.

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